/*
    * This file is part of Indicators.
    *
    * Indicators is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
    * Indicators is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with Indicators. If not, see <https://www.gnu.org/licenses/>.
   */
  package fr.inrae.agroclim.indicators.model.data.climate;
  
  import java.text.DateFormat;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Date;
  import java.util.EnumMap;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  
  import fr.inrae.agroclim.indicators.model.TimeScale;
  import fr.inrae.agroclim.indicators.model.data.DataLoadingListener;
  import fr.inrae.agroclim.indicators.model.data.FileLoader;
  import fr.inrae.agroclim.indicators.model.data.Resource;
  import fr.inrae.agroclim.indicators.model.data.Variable;
  import fr.inrae.agroclim.indicators.resources.I18n;
  import fr.inrae.agroclim.indicators.resources.Messages;
  import fr.inrae.agroclim.indicators.util.DateUtils;
  import fr.inrae.agroclim.indicators.util.StringUtils;
  import jakarta.xml.bind.annotation.XmlAccessType;
  import jakarta.xml.bind.annotation.XmlAccessorType;
  import jakarta.xml.bind.annotation.XmlElement;
  import jakarta.xml.bind.annotation.XmlTransient;
  import jakarta.xml.bind.annotation.XmlType;
  import lombok.Getter;
  import lombok.Setter;
  import lombok.extern.log4j.Log4j2;
  import tools.jackson.databind.MappingIterator;
  import tools.jackson.databind.ObjectReader;
  import tools.jackson.dataformat.csv.CsvMapper;
  import tools.jackson.dataformat.csv.CsvReadFeature;
  import tools.jackson.dataformat.csv.CsvSchema;
  
  /**
   * Load climate data from file.
   *
   * Last changed : $Date$
   *
   * @author $Author$
   * @version $Revision$
   */
  @XmlAccessorType(XmlAccessType.FIELD)
  @XmlType(propOrder = {"separator", "headers", "midnight", "endYear", "startYear"})
  @Log4j2
  public final class ClimateFileLoader extends FileLoader implements ClimateLoader {
      /**
       * UUID for Serializable.
       */
      private static final long serialVersionUID = 1913730755957817418L;
  
      /**
       * Localized date format for log message.
       */
      @XmlTransient
      private DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.SHORT);
  
      /**
       * Localized datetime format for log message.
       */
      @XmlTransient
      private DateFormat dateTimeFormat = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT);
  
      /**
       * Hour of midnight (0 for 0-23 or 24 for 1-24).
       */
      @Getter
      @Setter
      @XmlElement
      private Integer midnight = 0;
  
      /**
       * Headers of CSV file.
       */
      @Getter
      @Setter
      @XmlElement(name = "header")
      private String[] headers;
 
     /**
      * CSV separator.
      */
     @Getter
     @Setter
     @XmlElement
     private String separator = Resource.DEFAULT_SEP;
 
     /**
      * Calculator to compute ETP from climatic daily data.
      */
     @Setter
     @XmlTransient
     private EtpCalculator etpCalculator;
 
     /**
      * End year of data filtering (included).
      */
     @Getter
     @Setter
     private Integer endYear;
 
     /**
      * Start year of data filtering (included).
      */
     @Getter
     @Setter
     private Integer startYear;
 
     /**
      * Related time scales.
      */
     @Getter
     @Setter
     @XmlTransient
     private TimeScale timeScale = TimeScale.DAILY;
 
     /**
      * Constructor.
      */
     public ClimateFileLoader() {
         setDataFile(DataLoadingListener.DataFile.CLIMATIC);
     }
 
     /**
      * Constructor.
      *
      * @param csvFile
      *            relative path of CSV file
      * @param csvHeaders
      *            CSV headers
      * @param csvSeparator
      *            CSV separator
      */
     public ClimateFileLoader(final String csvFile, final String[] csvHeaders,
             final String csvSeparator) {
         this();
         setPath(csvFile);
         this.headers = csvHeaders;
         this.separator = csvSeparator;
     }
 
     /**
      * Ensure climatic data are ordered and there is not any missing.
      *
      * @param previous previous data
      * @param current current data to check
      * @param line line number
      * @param path file path
      */
     void checkDate(final ClimaticDailyData previous, final ClimaticDailyData current, final int line,
             final String path) {
         if (previous == null || current == null) {
             return;
         }
         final DateFormat df;
         if (timeScale == null) {
             throw new IllegalStateException("timeScale must not be null!");
         }
         final long delta;
         switch (timeScale) {
         case DAILY -> {
             df = dateFormat;
             delta = DateUtils.NB_OF_MS_IN_DAY;
         }
         case HOURLY -> {
             df = dateTimeFormat;
             delta = DateUtils.NB_OF_MS_IN_HOUR;
         }
         default -> throw new IllegalStateException("TimeScale not handled: " + timeScale);
         }
         if (previous.getDate() != null && current.getDate() != null) {
             final long previousTime = previous.getDate().getTime();
             final long currentTime = current.getDate().getTime();
             final long interval = currentTime - previousTime;
             if (interval < 0) {
                 current.getErrors().add(
                         Messages.format("error.day.succession", path, line,
                                 df.format(current.getDate()),
                                 df.format(previous.getDate())
                                 )
                         );
                 return;
             }
             if (interval == 0) {
                 current.getErrors().add(Messages.format("error.day.duplicate", path, line,
                         df.format(previous.getDate())));
                 return;
             }
             if (interval > delta) {
                 current.getErrors().add(Messages.format("error.day.missing", path, line, df.format(current.getDate())));
             }
         } else {
             current.getErrors().add(Messages.format("error.date.notread"));
         }
     }
 
     @Override
     public ClimateFileLoader clone() {
         final ClimateFileLoader clone = new ClimateFileLoader();
         clone.etpCalculator = etpCalculator.clone();
         clone.setPath(getPath());
         clone.headers = headers;
         clone.separator = separator;
         return clone;
     }
 
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
             return true;
         }
         if (obj == null) {
             return false;
         }
         if (getClass() != obj.getClass()) {
             return false;
         }
         final ClimateFileLoader other = (ClimateFileLoader) obj;
         if (!Objects.equals(this.separator, other.separator)) {
             return false;
         }
         if (!Objects.equals(this.getPath(), other.getPath())) {
             return false;
         }
         if (!Arrays.deepEquals(this.headers, other.headers)) {
             return false;
         }
         if (!Objects.equals(this.etpCalculator, other.etpCalculator)) {
             return false;
         }
         if (!Objects.equals(this.endYear, other.endYear)) {
             return false;
         }
         return Objects.equals(this.startYear, other.startYear);
     }
 
     @Override
     public Map<String, String> getConfigurationErrors() {
         final Map<String, String> errors = new HashMap<>();
         if (getPath() == null) {
             errors.put("climate.file", "error.evaluation.climate.file.missing");
         }
         if (!getFile().exists()) {
             errors.put("climate.file", "error.evaluation.climate.file.doesnotexist");
         } else if (getFile().length() == 0) {
             errors.put("climate.file", "error.evaluation.climate.file.empty");
         }
         if (separator == null) {
             errors.put("climate.separator", "error.evaluation.climate.separator.missing");
         } else if (separator.isEmpty()) {
             errors.put("climate.separator", "error.evaluation.climate.separator.empty");
         }
         if (headers == null) {
             errors.put("climate.header", "error.evaluation.climate.header.missing");
         }
         if (timeScale == TimeScale.DAILY && etpCalculator == null) {
             errors.put("climate.etpCalculator", "error.evaluation.climate.etpCalculator.missing");
         }
         if (errors.isEmpty()) {
             return null;
         }
         return errors;
     }
 
     /**
      * @return Calculator to compute ETP from climatic daily data.
      */
     private EtpCalculator getEtpCalculator() {
         if (timeScale != TimeScale.DAILY) {
             throw new UnsupportedOperationException("Only daily data should have ETP!");
         }
         if (etpCalculator == null) {
             throw new RuntimeException("EtpCalculator not set!");
         }
         return etpCalculator;
     }
 
     /**
      * @return Missing climatic variables, to check in aggregation indicators.
      */
     @Override
     public Collection<String> getMissingVariables() {
         final List<String> all = new ArrayList<>(ClimaticDailyData.getAllColumnNames(timeScale));
         if (headers != null) {
             for (final String header : headers) {
                 all.remove(header.toLowerCase());
             }
         }
         return all;
     }
 
     @Override
     public Set<Variable> getProvidedVariables() {
         return super.getProvidedVariables(headers);
     }
 
     @Override
     public Set<Variable> getVariables() {
         if (etpCalculator == null) {
             return new HashSet<>();
         }
         return etpCalculator.getVariables();
     }
 
     @Override
     public int hashCode() {
         final int prime1 = 7;
         final int prime = 71;
         int hash = prime1;
         hash = prime * hash + Objects.hashCode(this.getPath());
         hash = prime * hash + Arrays.deepHashCode(this.headers);
         hash = prime * hash + Objects.hashCode(this.separator);
         hash = prime * hash + Objects.hashCode(this.etpCalculator);
         hash = prime * hash + Objects.hashCode(this.endYear);
         hash = prime * hash + Objects.hashCode(this.startYear);
         return hash;
     }
 
     @Override
     public List<ClimaticDailyData> load() {
         LOGGER.trace("start");
         if (getPath() == null || getFile() == null) {
             throw new RuntimeException("no file defined for climate.");
         }
         if (separator == null) {
             throw new RuntimeException("no separator defined for climate.");
         }
         LOGGER.trace("headers: {}", StringUtils.join(headers, ","));
         final List<ClimaticDailyData> data = new ArrayList<>();
         final List<String> headerFiltered = new ArrayList<>();
         final Map<Variable, Integer> valuesCol = new EnumMap<>(Variable.class);
         int yearCol = -1;
         int monthCol = -1;
         int dayCol = -1;
         int hourCol = -1;
         final String[] headersFromFile = getHeaders(getFile(), separator.charAt(0));
         String[] usedHeaders;
 
         if (headers == null) {
             usedHeaders = headersFromFile;
         } else {
             usedHeaders = headers;
         }
         for (int i = 0; i < usedHeaders.length; i++) {
             final String header = usedHeaders[i];
             final String lcHeader = header.toLowerCase();
             final int index = ClimaticDailyData.getAllColumnNames(timeScale).indexOf(lcHeader);
             if (index != -1) {
                 headerFiltered.add(header.substring(0, 1).toUpperCase() + lcHeader.substring(1));
                 if (header.equals("year")) {
                     yearCol = i;
                     continue;
                 }
                 if (header.equals("month")) {
                     monthCol = i;
                     continue;
                 }
                 if (header.equals("day")) {
                     dayCol = i;
                     continue;
                 }
                 if (header.equals("hour")) {
                     hourCol = i;
                     continue;
                 }
                 valuesCol.put(Variable.getByName(header), i);
             } else {
                 headerFiltered.add(null);
             }
         }
 
         LOGGER.trace("userHeadersArray: {}", StringUtils.join(headerFiltered, ","));
 
         LOGGER.trace("year: {}, month: {}, day: {}", yearCol, monthCol, dayCol);
         LOGGER.trace("variables: {}", valuesCol);
         if (usedHeaders.length != headersFromFile.length) {
             final I18n i18n = new I18n("fr.inrae.agroclim.indicators.resources.messages", Locale.getDefault());
             final String msg = i18n.format("error.climate.wrong.headers", headersFromFile.length,
                     StringUtils.join(headersFromFile, ", "), usedHeaders.length, StringUtils.join(usedHeaders, ", "));
             throw new RuntimeException(msg);
         }
         fireDataLoadingStartEvent("Start of reading file: " + getFile().getName());
 
         final CsvSchema schema = CsvSchema.emptySchema().withSkipFirstDataRow(true)//
                 .withColumnSeparator(separator.charAt(0));
         final CsvMapper mapper = CsvMapper.builder() //
                 .configure(CsvReadFeature.WRAP_AS_ARRAY, true) //
                 .build();
 
         final ObjectReader objReader = mapper.readerFor(String[].class).with(schema);
         try (MappingIterator<String[]> it = objReader.readValues(getFile())) {
             ClimaticDailyData previous = null;
             while (it.hasNext()) {
                 final int lineNumber = it.currentLocation().getLineNr();
                 final String[] row = it.next();
                 final Integer year = this.parseInt(row[yearCol], null);
                 if (startYear != null && year < startYear || endYear != null && year > endYear) {
                     continue;
                 }
                 final ClimaticDailyData dailyData = new ClimaticDailyData();
                 dailyData.setTimescale(timeScale);
                 dailyData.setYear(year);
                 dailyData.setMonth(this.parseInt(row[monthCol], null));
                 dailyData.setDay(this.parseInt(row[dayCol], null));
                 if (timeScale == TimeScale.HOURLY) {
                     final int hour = Integer.parseInt(row[hourCol]);
                     if (midnight == DateUtils.NB_OF_HOURS_IN_DAY && hour == DateUtils.NB_OF_HOURS_IN_DAY) {
                         final long newTime = dailyData.getDate().getTime() + DateUtils.NB_OF_MS_IN_DAY;
                         final Date newDate = new Date(newTime);
                         dailyData.setYear(DateUtils.getYear(newDate));
                         dailyData.setMonth(DateUtils.getMonth(newDate));
                         dailyData.setDay(DateUtils.getDom(newDate));
                         dailyData.setHour(0);
                     } else {
                         dailyData.setHour(hour);
                     }
                 }
                 valuesCol.forEach((variable, index) -> {
                     if (row[index] != null && !row[index].isEmpty()) {
                         dailyData.setValue(variable, Double.valueOf(row[index]));
                     }
                 });
                 if (timeScale == TimeScale.DAILY) {
                     dailyData.setEtpCalculator(getEtpCalculator());
                 }
                 dailyData.check(lineNumber, getFile().getName());
                 checkDate(previous, dailyData, lineNumber, getFile().getName());
                 fireDataLoadingAddEvent(dailyData);
                 data.add(dailyData);
                 previous = dailyData;
             }
             fireDataLoadingEndEvent("End of reading " + getFile().getName());
         }
         return data;
     }
 
     /**
      * Parse String to Integer, like {@code Integer.parseInt} method.
      * @param value the string value to parsing
      * @param defaultValue if not possible to parse, this value will be returned
      * @return value parsed or defaultValue
      */
     private Integer parseInt(final String value, final Integer defaultValue) {
         Integer ret;
         try {
             ret = Integer.valueOf(value);
         } catch (final NumberFormatException e) {
             ret = defaultValue;
         }
         return ret;
     }
     /**
      * @param locale locale for date formatter
      */
     public void setLocale(final Locale locale) {
         dateFormat = DateFormat.getDateInstance(DateFormat.SHORT, locale);
         dateTimeFormat = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, locale);
     }
 }